Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
Fukui Institute for Fundamental Chemistry, Kyoto University, Sakyo-ku, Kyoto 606-8103, Japan.
J Am Chem Soc. 2023 Dec 6;145(48):26202-26212. doi: 10.1021/jacs.3c08740. Epub 2023 Nov 21.
The covalent inhibition of a target protein has gained widespread attention in the field of drug discovery. Most of the current covalent drugs utilize the high reactivity of cysteines toward modest electrophiles. However, there is a growing need for warheads that can target lysine residues to expand the range of covalently druggable proteins and to deal with emerging proteins with mutations resistant to cysteine-targeted covalent drugs. We have recently developed an -acyl--alkyl sulfonamide (NASA) as a lysine-targeted electrophile. Despite its successful application, this NASA warhead suffered from instability in physiological environments, such as serum-containing medium, because of its high intrinsic reactivity. In this study, we sought to modify the structure of the NASA warhead and found that -acyl--aryl sulfonamides (ArNASAs) are promising electrophiles for use in a lysine-targeted covalent inhibition strategy. We prepared a focused library of ArNASA derivatives with diverse structures and reactivity and identified several warhead candidates with suppressed hydrolysis-mediated inactivation and reduced nonspecific reactions with off-target proteins, without sacrificing the reactivity toward the target. These reaction properties enabled the improved covalent inhibition of intracellular heat shock protein 90 (HSP90) in the presence of serum and the development of the first irreversible inhibitor for ibrutinib-resistant Bruton's tyrosine kinase (BTK) bearing the C481S mutation. This study clearly demonstrated the use of a set of ArNASA warheads to create highly potent covalent drugs and highlighted the importance of enriching the current arsenal of lysine-reactive warheads.
靶向蛋白的共价抑制在药物发现领域受到广泛关注。目前大多数共价药物利用半胱氨酸对中等亲电试剂的高反应性。然而，越来越需要能够靶向赖氨酸残基的弹头，以扩大可共价修饰的蛋白质范围，并应对对针对半胱氨酸的共价药物具有突变抗性的新兴蛋白质。我们最近开发了一种酰基-烷基磺酰胺 (NASA) 作为靶向赖氨酸的亲电试剂。尽管该 NASA 弹头已成功应用，但由于其高固有反应性，在含有血清的培养基等生理环境中稳定性较差。在这项研究中，我们试图修饰 NASA 弹头的结构，发现酰基-芳基磺酰胺 (ArNASA) 是一种很有前途的用于赖氨酸靶向共价抑制策略的亲电试剂。我们制备了具有不同结构和反应性的 ArNASA 衍生物的聚焦文库，并鉴定了几个具有抑制水解介导失活和减少与非靶标蛋白非特异性反应的弹头候选物，而不牺牲其对靶标的反应性。这些反应特性使在存在血清的情况下能够更有效地抑制细胞内热休克蛋白 90 (HSP90)，并开发了首例具有 C481S 突变的对伊布替尼耐药布鲁顿酪氨酸激酶 (BTK) 的不可逆抑制剂。这项研究清楚地表明，使用一组 ArNASA 弹头可以创造出高效的共价药物，并强调了丰富当前赖氨酸反应性弹头库的重要性。
